Apparatus and method for grinding compression line spring

ABSTRACT

Disclosed herein is an apparatus for grinding a compression line spring. The apparatus includes a lower chain conveyor ( 100 ), an upper chain conveyor ( 200 ), and grinding units ( 300 ). The lower chain conveyor includes chain units ( 110 ) and ( 110 ′) provided facing each other at positions spaced apart from each other. Each chain unit ( 110 ), ( 110 ′) includes first V-shaped blocks ( 115 ) for supporting compression line springs. The upper chain conveyor includes chain units ( 210 ) and ( 210 ′) provided facing each other at positions spaced apart from each other. Each chain unit ( 210 ), ( 210 ′) includes second V-shaped blocks ( 215 ) for compressing downward upper portions of the compression line springs seated on the first V-shaped blocks ( 115 ) and thus supporting the compression line springs. The grinding units ( 300 ) grind seat surfaces formed on opposite ends of the compression line springs that are being moved by the lower chain conveyor and the upper chain conveyor.

TECHNICAL FIELD

The present invention generally relates to apparatuses and methods forgrinding seat surfaces formed on opposite ends of compression linesprings and, more particularly, to an apparatus and method for grindingseat surfaces formed on opposite ends of compression line springs whilethe compression line springs are continuously transferred by a chainconveyor.

BACKGROUND ART

FIG. 1 is a view showing the structure of a compression line spring.

Generally, the compression line spring 10 is a spring that ismanufactured by spirally winding a linear spring material. Thecompression line spring is processed through a seat-surface grindingprocess so that seat surfaces 10 a and 10 b formed on opposite ends ofthe compression line spring 10 are oriented perpendicular to a shaft Sof the spring 10.

FIG. 2 is a plan view showing the construction of a conventionalapparatus for grinding compression line springs. FIG. 3 is a side viewshowing the construction of the conventional grinding apparatus.

The conventional grinding apparatus includes a turntable 20 that rotateswith a plurality of compression line springs 10 fixed to the turntable20, and a plurality of grinding wheels 30 that are disposed above andbelow the turntable 20 and face each other with the turntable 20disposed therebetween. The grinding wheels 30 grind the seat surfaces ofthe compression line springs 10 that are being transferred by therotation of the turntable.

A plurality of installation holes 21 are formed in the turntable 20, andcompression line springs are fitted into the installation holes 21. Theinstallation holes 21 have diameters corresponding to outer diameters ofthe compression line springs to be ground so that the compression linesprings can be reliably supported on the turntable while the operationof grinding the compression line springs is conducted.

However, the conventional grinding apparatus has the following problems.

When it is required in a separate operation to grind compression linesprings having a different dimension, the entirety of the turntable mustbe replaced with another one. This makes the work complex. In addition,different kinds of turntables corresponding to the kinds of compressionline springs must be prepared, thus increasing the cost of equipment.

That is, the installation holes formed in the turntable cannot beadjusted in diameter. Thus, it is impossible to install compression linesprings having outer diameters greater than the diameter of theinstallation holes. In the case of compression line springs havingexcessively smaller outer diameters than the diameter of theinstallation holes, when the grinding process is conducted, thecompression line springs cannot be reliably supported. Thus, vibrationsmay occur. Furthermore, there is the likelihood of the compression linesprings being removed from the installation holes, which may lead to anaccident.

Therefore, there is a problem in that the turntable must be replacedwith another one when it is required to grind other kinds of compressionline springs.

DISCLOSURE Technical Problem

Accordingly, the present invention has been made keeping in mind theabove problems occurring in the prior art, and an object of the presentinvention is to provide apparatus and method for grinding compressionline springs that can grind different kinds of compression line springswithout replacing a main part with another one so long as the diametersof the compression line springs fall within a predetermined range.

Technical Solution

In order to accomplish the above object, in an aspect, the presentinvention provides an apparatus for grinding a compression line spring,including: a lower chain conveyor including a pair of chain unitsprovided facing each other at positions spaced apart from each other,each of the chain units including a plurality of first V-shaped blocksfor supporting compression line springs; an upper chain conveyorincluding a pair of chain units provided facing each other at positionsspaced apart from each other, each of the chain units comprising aplurality of second V-shaped blocks for compressing downward upperportions of the compression line springs seated on the first V-shapedblocks and thus supporting the compression line springs; and a pluralityof grinding units for grinding seat surfaces formed on opposite ends ofthe compression line springs that are moved by the lower chain conveyorand the upper chain conveyor.

In another aspect, the present invention provides a method for grindinga compression line spring, including: an operation (S110) of fixingcompression line springs in place using first V-shaped blocks and secondV-shaped blocks respectively provided in a lower chain conveyor and anupper chain conveyor and transferring the compression line springs in ahorizontal direction using the lower chain conveyor and the upper chainconveyor; and an operation (S120) of grinding, using grinding units,seat surfaces formed on opposite ends of the compression line springsthat are transferred in the operation (S110).

As described above, in apparatus and method for grinding compressionline springs according to the present invention, when it is required ina separate operation to grind compression line springs having adifferent dimension, appropriate conditions for grinding the compressionline springs can be easily embodied by simple setting manipulationwithout need for conventional complex operation of replacing a turntablewith another one. Therefore, the efficiency of the operation of grindingcompression line springs can be enhanced. Moreover, because there is noneed for preparing different kinds of turntables, related cost can bereduced.

DESCRIPTION OF DRAWINGS

FIG. 1 is a view showing the structure of a compression line spring;

FIG. 2 is a plan view showing the construction of a conventionalapparatus for grinding a compression line spring;

FIG. 3 is a side view showing the construction of the conventionalgrinding apparatus;

FIG. 4 is a front view illustrating the construction of a grindingapparatus according to the present invention;

FIG. 5 is a plan view illustrating the construction of the grindingapparatus according to the present invention;

FIG. 6 is a side view illustrating critical parts of the grindingapparatus according to the present invention;

FIG. 7 is a front view illustrating the construction of a lower chainconveyor according to the present invention;

FIG. 8 is a plan view illustrating the construction of the lower chainconveyor according to the present invention;

FIG. 9 is a perspective view showing the coupling of first V-shapedblocks to a chain according to the present invention;

FIG. 10 is a front view illustrating the construction of an upper chainconveyor according to the present invention;

FIG. 11 is a plan view illustrating the construction of the upper chainconveyor according to the present invention;

FIG. 12 is a perspective view showing the coupling of second V-shapedblocks to a chain according to the present invention;

FIG. 13 is a view showing in detail the installation of pressing-blocksaccording to the present invention;

FIG. 14 is a side view showing the installation structure of grindingunits according to the present invention;

FIG. 15 is a front view showing the structure of a distance adjustmentmeans according to the present invention; and

FIG. 16 is a side view showing the structure of the distance adjustmentmeans according to the present invention.

DESCRIPTION OF THE REFERENCE NUMERALS IN THE DRAWINGS

100: lower chain conveyor 110: front chain unit

110′: rear chain unit 115: first V-shaped block

118: spline shaft 130,130′: first screw shaft

140: transfer nut 150: belt

200: upper chain conveyor 210: front chain unit

210′: rear chain unit 214: chain

215: second V-shaped block 218: spline shaft

230: second screw shaft 240: transfer nut

250: motor 260: compression block

261: pin 270: spring

300: grinding unit 330; transfer table

340: transfer nut 350: third screw shaft

360: fastening plate 370: transfer nut

380: fourth screw shaft 400: motor

410: reducer 411,412: output shaft

420: first universal joint 430: second universal joint

500: distance adjustment means 510: lift frame

520: rail 531,532: inclined block

531′, 532′: inclined rail 540: fifth screw shaft

543: handle 551,552: fixed block

560: fixed frame

BEST MODE

Hereinafter, an embodiment of the present invention will be describedwith reference to the attached drawings. If in the specification,detailed descriptions of well-known functions or configurations wouldunnecessarily obfuscate the gist of the present invention, the detaileddescriptions will be omitted.

FIG. 4 is a front view illustrating critical parts of an apparatus forgrinding a compression line spring according to the present invention.FIG. 5 is a plan view illustrating the critical parts of the grindingapparatus according to the present invention. FIG. 6 is a side viewillustrating the critical parts of the grinding apparatus according tothe present invention.

The grinding apparatus according to the present invention ischaracterized in that with regard to a compression line spring 10 havingan outer diameter within a predetermined range, a part for fixing thecompression line spring in place can be easily re-set by simplemanipulation without need for replacing it with another one, and thenoperation of grinding the compression line spring can be conducted. Thegrinding apparatus includes a lower chain conveyor 100, an upper chainconveyor 200, and grinding units 300.

Reference numeral 280 of FIG. 6 denotes a nozzle that sprays cutting oilto cool heat generated during a process of grinding the compression linespring and prevent dust from scattering.

FIG. 7 is a front view illustrating the construction of the lower chainconveyor according to the present invention. FIG. 8 is a plan viewillustrating the construction of the lower chain conveyor according tothe present invention. FIG. 9 is a perspective view showing the couplingof first V-shaped blocks to a chain according to the present invention.

The lower chain conveyor 100 includes a pair of chain units 110 and110′. The chain units 110 and 110′ are disposed facing each other atpositions spaced apart from each other.

Meanwhile, the two chain units 110 and 110′ substantially have the sameconstruction with a difference only in position; therefore, the samereference numerals are used to explain parts of the chain units 110 and110′.

Each chain unit 110, 110′ includes a frame 111, sprockets 112 and 113installed on respective opposite left and right ends of the frame 111, achain 114 that is supported by the frame 111 and the sprockets 112 and113 and rotated therearound, and a plurality of first V-shaped blocks115 that is installed on the chain 114 and provide space to seat thecompression line springs therein.

Each first V-shaped block 115 is coupled to the chain 114 by a pin 116fastened through the chain 114. The first V-shaped block 115 coupled tothe chain 114 by the pin 116 is configured so as to be finely rotatablearound the pin 116. Due to the above-mentioned configuration, the firstV-shaped block 115 is finely rotated around the pin 116 depending bothon the orientation of the compression line spring seated onto the firstV-shaped block 115 and on the orientation of a second V-shaped blockcompressing and supporting an upper end of the compression line springand is thus oriented corresponding to the orientations of thecompression line spring and the second V-shaped block. In this way, thefirst V-shaped block 115 can more stably support the compression linespring.

Meanwhile, the sprockets 112 and 113 that are provided in the two chainunits 110 and 110′ spaced apart from each other are respectively coupledto spline shafts 117 and 118 each of which extends a predeterminedlength through the two chain units 110 and 110′, whereby the sprockets112 and 113 are rotated along with the spline shafts 117 and 118.Furthermore, the chain unit 110 disposed at a front side of theapparatus is configured to be movable along the spline shaft 117 and 118toward or away from the rear chain unit 110′.

Therefore, a distance D1 between the two chain units 110 and 110′ can beappropriately adjusted by moving the front chain unit 110 depending onthe length of the compression line springs.

To achieve the purpose of moving the front chain unit 110, the frontchain unit 110 and the rear chain unit 110′ are connected to each otherby one or more linear guides 120. The front chain unit 110 is configuredto move along the linear guides 120.

The front chain unit 110 includes transfer nuts 140 that are coupled toone or more first screw shafts 130 and 130′ which horizontally extend apredetermined length through the rear chain unit 110′. Therefore, thefront chain unit 110 is moved along with the transfer nuts 140 byrotation of the first screw shafts 130 and 130′.

FIGS. 7 and 8 illustrate the configuration in which the first screwshafts 130 and 130′ are respectively installed in the opposite left andright sides of the lower chain conveyor 100. In this embodiment, thefirst screw shafts 130 and 130′ are automatically rotated by a powersource such as a motor, but they may be configured to be manuallyrotated by an operator.

FIG. 10 is a front view illustrating the construction of the upper chainconveyor according to the present invention. FIG. 11 is a plan viewillustrating the construction of the upper chain conveyor according tothe present invention. FIG. 12 is a perspective view showing thecoupling of second V-shaped blocks to the chain according to the presentinvention. FIG. 13 is a view showing in detail the installation ofpressing blocks according to the present invention.

The upper chain conveyor 200 includes a pair of chain units 210 and210′. The chain units 210 and 210′ are disposed facing each other atpositions spaced apart from each other. Preferably, the chain units 210and 210′ are respectively disposed vertically above the chain units 110and 110′ of the lower chain conveyor 100.

According to the above construction, the second V-shaped blocks 215provided in the chain units 210 and 210′ of the upper chain conveyor 200are disposed vertically above the respective first V-shaped blocks 115provided in the chain units 110 and 110′ of the lower chain conveyor100. The first and second V-shaped blocks face each other with thecompression line springs interposed therebetween and thus fix thecompression line springs in place.

Meanwhile, the two chain units 210 and 210′ substantially have the sameconstruction with a difference only in position; therefore, the samereference numerals are used to explain parts of the chain units 210 and210′.

Each chain unit 210, 210′ includes a frame 211, sprockets 212 and 213installed on respective opposite left and right ends of the frame 211, achain 214 that is supported by the frame 211 and the sprockets 212 and213 and rotated therearound, and a plurality of second V-shaped blocks215 that is installed on the chain 214 and compresses and supports theupper portions of the compression line springs seated on the respectivefirst V-shaped blocks 115.

In the same manner as the first V-shaped block 115, each second V-shapedblock 215 is coupled to the chain 214 by a pin 216 fastened through thechain 210 and configured so as to be finely rotatable around the pin216.

Meanwhile, the sprockets 212 and 213 that are provided in the two chainunits 210 and 210′ spaced apart from each other are respectively coupledto spline shafts 217 and 218 each of which extends a predeterminedlength through the two chain units 210 and 210′, whereby the sprockets212 and 213 are rotated along with the spline shafts 217 and 218.Furthermore, the chain unit 210 disposed at the front side of theapparatus is configured to be movable along the spline shaft 217 and 218toward or away from the rear chain unit 210′.

The sprockets 212 that are disposed at the left side of the associateddrawing are idle sprockets, which rotate under no-load conditionswithout being connected to any power source. The idle sprockets 212 maybe coupled to each other by a general shaft rather than by the splineshaft 217.

According to the above-mentioned construction, a distance D2 between thetwo chain units 210 and 210′ can be appropriately adjusted by moving thefront chain unit 210 depending on the length of the compression linesprings.

To achieve the purpose of moving the front chain unit 210, the frontchain unit 210 and the rear chain unit 210′ are connected to each otherby one or more linear guides 220. The front chain unit 210 is configuredto move along the linear guides 220.

Furthermore, the front chain unit 210 includes a transfer nut 240 thatis coupled to a second screw shaft 230 that horizontally extends apredetermined length through the rear chain unit 210′. Therefore, thefront chain unit 210 is moved along with the transfer nut 240 byrotation of the second screw shaft 230.

Preferably, the second screw shaft 230 and the first screw shafts 130and 130′ are connected and interlocked with each other so that the frontchain unit 210 of the upper chain conveyor 200 and the front chain unit110 of the lower chain conveyor 100 can be moved together.

For this, the first screw shafts 130 and 130′ and the second screw shaft230 are connected to each other by a power transmission means such aschains or belts (150: refer to FIGS. 8 and 11). According to thisconstruction, when the first screw shafts 130 and 130′ rotate, thesecond screw shaft 230 rotates along with the first screw shafts 130 and130′. In the same manner, when the second screw shaft 230 rotates, thefirst screw shafts 130 and 130′ also rotate along with the second screwshaft 230.

With regard to the interlocking rotation of the first screw shaft 130and 130′ and the second screw shaft 230, the second screw shaft 230 maybe connected to a motor 250 and rotated by it so that the two frontchain units 110 and 210 can be moved by the operation of the motor 250.Alternatively, the two front chain units 110 and 210 may be moved bymanually manipulating the first screw shafts 130 and 130′.

A left-right width (L2: refer to FIG. 10) of the upper chain conveyor200 is shorter than a left-right width (L1: refer to FIG. 7) of thelower chain conveyor 100.

Preferably, the upper chain conveyor 200 further includes a plurality ofcompression blocks 260 that press the chain 214 downward so that thesecond V-shaped blocks 215 can reliably come into close contact with thecompression line springs, and a plurality of springs 270 thatelastically support the compression blocks 260.

The compression blocks 260 are installed under the frames 211 of thechain units 210 and 210′. The compression blocks 260 installed in theabove manner are disposed vertically above a portion of the chain 214that passes under lower ends of the frames 211 and thus compress thechain 214 downward.

Meanwhile, each of the compression blocks 260 compresses the chain 214downward so that one or two corresponding second V-shaped blocks 215 cancome into close contact with the respective compression line springs.For reference, FIG. 13 illustrates the structure in which two secondV-shaped blocks 215 are compressed by a single compression block 260.

The compression blocks 260 are coupled to each other by pins 261.According to this construction, each compression block 260 is configuredso as to be restrictively rotatable around the corresponding pin 261,whereby each two of the second V-shaped blocks 215 that are compressedby a corresponding single compression block 260 can be compressed underdifferent conditions.

That is, there may be a deviation in orientation or outer diameter ofthe compression line springs 10 supported by the first and second blocks115 and 215. However, if the second V-shaped blocks 215 are compressedat the same pressure without taking such deviation into account, thesecond V-shaped block 215 that is disposed above the compression linespring having a comparatively small diameter may not reliably come intoclose contact with the upper portion of the compression line spring. Inthis case, the compression line spring may be removed from its correctposition during the process of grinding the seat surfaces of thecompression line spring.

However, in the present invention, the compression blocks 260 arecoupled to each other by the pins 261, whereby the compression blocks260 are configured so as to be slightly movable although this movementis restricted. In this case, appropriate movement of the compressionblocks 260 compensates for the deviation in orientation or outerdiameter of the compression line springs. Consequently, the compressionline springs can be more stably supported by the V-shaped blocks.

The lower chain conveyor 100 and the upper chain conveyor 200 areoperated by power provided from a single motor.

In more detail with reference to FIG. 5, the motor 400 for providingpower to operate the lower chain conveyor 100 and the upper chainconveyor 200 is connected to a reducer 410. The reducer 410 reduces thespeed of rotation input from the motor 400 at a predetermined ratio andthen outputs power reduced in speed via two output shafts 411 and 412.Any one of the two output shafts 411 and 412 provided in the reducer 410is coupled by a first universal joint 420 to the spline shaft 118provided in the lower chain conveyor 100. The other output shaft 411 or412 is coupled by a second universal joint 430 to the spline shaft (218:refer to FIG. 11) provided in the upper chain conveyor 200.

Meanwhile, although the internal construction of the reducer 410 is notillustrated in detail, a plurality of gears are provided in the reducer410 so as to reduce the speed of rotation input from the motor 400 at apredetermined ratio. Such construction of the reducer 410 is a wellknown and widely used technique. Therefore, further explanation of thereducer 410 will be omitted.

FIG. 14 is a side view illustrating the installation structure of thegrinding units according to the present invention.

The grinding units 300 are disposed on opposite front and rear sides ofthe lower chain conveyor 100 and grind seat surfaces of opposite ends ofthe compression line springs 10 that are being moved by the lower chainconveyor 100 and the upper chain conveyor.

Some of the grinding units 300 are disposed ahead of the lower chainconveyor 100, and the other grinding units 300 are disposed behind thelower chain conveyor 100.

Each grinding unit 300 includes a motor 310, and a grinding wheel 320that is rotated by the motor 310 to conduct the grinding operation.

Preferably, each grinding unit 300 is configured such that an operatorcan adjust the position thereof depending both on the length of thecompression line spring 10 and on the depth of cut. For this, a transfertable 330 is provided under the grinding unit 300, and a transfer nut340 and a third screw shaft 350 are installed to transfer the transfertable 330.

Meanwhile, the transfer table 330, the transfer nut 340, and the thirdscrew shaft 350 are installed on each of the opposite front and rearsides of the lower chain conveyor 100 so that the grinding unitsdisposed ahead of the lower chain conveyor 100 and the grinding unitsdisposed behind the lower chain conveyor 100 can be independently moved.

The grinding units 300 are fastened on an upper surface of each transfertable 330.

The transfer nut 340 is fastened to a lower surface of the transfertable 330.

The third screw shaft 350 extends in the front-rear directionperpendicular to the lower chain conveyor 100 and is coupled to thetransfer nut 340.

When the operator rotates a handle 351 coupled to the third screw shaft350, the transfer nut 340 is moved by the rotation of the third screwshaft 350. The transfer table 330 is thus moved by the movement of thetransfer nut 340, whereby the position of the grinding unit 300 can beadjusted.

Meanwhile, to individually adjust the position of each grinding unit300, a fastening plate 360 is installed under a lower surface of eachgrinding unit 300. A transfer nut 370 is provided under a lower surfaceof the fastening plate 360. A fourth screw shaft 380 is installed on anupper surface of the transfer table 330 and is coupled to the transfernut 370 so that the transfer nut 370 is moved by rotation of the fourthscrew shaft 380.

Preferably, the pitch of the fourth screw shaft 380 is less than that ofthe third screw 350 so that the position of each grinding unit 300 canbe more precisely adjusted by the fourth screw shaft 380.

FIG. 15 is a front view showing the structure of a distance adjustmentmeans according to the present invention. FIG. 16 is a side view showingthe structure of the distance adjustment means according to the presentinvention.

If it is required in a separate operation to grind compression linessprings having a different dimension, the distance between the firstV-shaped block 115 and the second V-shaped block 215 must be adjusted tocorrespond to the outer diameter of the compression line springs.

The distance adjustment means 500 for adjusting the distance between thefirst and second V-shaped blocks 115 and 215 includes a lift frame 510includes a lift frame 510, a rail 520, inclined blocks 531 and 532, afifth screw shaft 540, and fixed blocks 551 and 552.

The lift frame 510 is coupled to the upper chain conveyor 200 andconfigured to move upward or downward along with the upper chainconveyor 200.

The lift frame 510 has a reverse U shape that is open on a lower endthereof. An upper end of the upper chain conveyor 200 is inserted intothe lift frame 510.

The rail 520 extends in the left-right direction on an upper end of thelift frame 510. FIG. 16 illustrates the structure in which two rails 520are spaced apart from each other by a predetermined distance andinstalled parallel to each other.

The inclined blocks 531 and 532 are coupled to the rails 520 andconfigured to move along the rails 520. Inclined rails 531′ and 532′having a predetermined inclination angle ⊖ are respectively installed onthe inclined blocks 531 and 532.

In this embodiment, the two inclined blocks 531 and 532 are provided.The two inclined blocks 531 and 532 are installed on the rails 520 andconfigured to form a symmetrical structure facing each other atpositions spaced apart from each other by a predetermined distance.

The fifth screw shaft 540 is installed to pass through the two inclinedblocks 531 and 532 coupled to the rails 520 and is rotatably coupled toa support 511 installed on the lift frame 510.

The fifth screw shaft 540 includes a left-handed screw part 541 that isformed on one side of the fifth screw shaft 540 based on a medialportion thereof, and a right-handed screw part 542 that is formed on theother side thereof. Any one of the inclined blocks 531 is coupled to theleft-handed screw part 541, and the other inclined block 532 is coupledto the right-handed screw part 542 so that when the fifth screw shaft540 is rotated, the two inclined blocks 531 and 532 are moved toward oraway from each other.

In this embodiment, the two fixed blocks 551 and 552 are respectivelycoupled to the inclined blocks 531 and 532. The fixed blocks 551 and 552are fastened to a fixed frame 560 such that the fixed blocks 551 and 552are disposed vertically above the respective inclined blocks 531 and532.

In this way, the fixed blocks 551 and 552 installed on the fixed frame560 are coupled to the inclined rails 531′ and 532′ provided on theinclined blocks 531 and 532.

Therefore, when the operator rotates a handle 543 provided on the fifthscrew shaft 540, the two inclined blocks 531 are moved toward or awayfrom each other depending on the direction in which the handle 543 isrotated. During this process, the two inclined blocks 531 and 532 aremoved upward or downward by the inclined rails 531′ and 532′ and thefixed blocks 551 and 552 and thus move the lift frame 510 upward ordownward. Then, the upper chain conveyor 200 is moved upward or downwardby the vertical movement of the lift frame 510, whereby the distancebetween the first V-shaped block 115 and the second V-shaped block 215can be adjusted.

A method for grinding compression line springs using the grindingapparatus according to the present invention having the above-mentionedconstruction includes: operation S110 of fixing the compression linesprings 10 in place using the first and second V-shaped blocks 115 and215 provided in the lower and upper chain conveyors 100 and 200 andtransferring the compression line springs in the horizontal directionusing the lower and upper chain conveyors 100 and 200; and operationS120 of grinding, using the grinding units 300, the seat surfaces formedon the opposite ends of the compression line springs that are beingtransferred in operation S110.

In operation S110, the compression line springs 10 are seated on thefirst V-shaped blocks 115 provided in the lower chain conveyor 100, andthen the lower chain conveyor 100 and the upper chain conveyor 200 areoperated.

Such operation S110 preferably includes supplying compression linesprings from a separate compression-line-spring supply apparatus to thefirst V-shaped blocks 115 while the lower and upper chain conveyors 100and 200 are operated.

A well known robot arm or a well known automatic part feeder may be usedas the compression-line-spring supply apparatus.

Meanwhile, the compression line springs seated on the first V-shapedblocks 115 of the lower chain conveyor 100 are moved by the operation ofthe lower chain conveyor 100. After the compression line springs havemoved a predetermined distance, upper portions thereof are compressed bythe second V-shaped blocks 215 provided in the upper chain conveyor 200.Thereby, the compression line springs can be stably fixed in place bythe first and second V-shaped blocks 115 and 25.

As such, during the process of using the first and second V-shapedblocks 115 and 215 to fix the compressing line springs in place and movethem, the compression blocks 260 compress the chain 214 at apredetermined pressure corresponding to conditions of the compressionline springs. Thereby, the second V-shaped blocks 215 can reliably comeinto close contact with the compression line springs. Here, theconditions of the compression line springs may include a state wherebythe compression line springs are seated on the first V-shaped blocks115, or a deviation in the outer diameter of the compression linesprings.

Preferably, operation S101 of adjusting both the distance between thefront chain unit 110 and the rear chain unit 110′ of the lower chainconveyor 100 and the distance between the front chain unit 210 and therear chain unit 210′ of the upper chain conveyor 200 precedes operationS110.

In other words, when it is required in a separate operation to grindcompression line springs having a different dimension, for example, adifferent length, the front chain units 110 and 210 are moved and set topositions corresponding to the length of compression line springs to beground so that the first V-shaped block 115 and the second V-shapedblock 215 can support the compression line springs at appropriatepositions.

The movement of the front chain units 110 and 210 may be embodied by theoperator in such a way that the operator directly rotates the firstscrew shafts 130 and 130′ provided in the lower chain conveyor 100.Alternatively, it may be embodied by the operation of the motor 250connected to the second screw shaft 230.

The method may further include operation S102 of adjusting the height ofthe upper chain conveyor 200 that is combined with operation S101.

Operation S102 is conducted to grind other compression line springs witha different diameter. When the operator rotates the handle 543 providedon the fifth screw shaft 540, the inclined blocks 531 and 532 are movedby the rotation of the fifth screw shaft 540. Then, the inclined blocks531 and 532 are slowly moved downward or upward by the fixed blocks 551and 552 and the inclined rails 531′ and 532′, whereby the height of theupper chain conveyor 200 can be adjusted.

In operation S120, the compression line springs are moved by theoperation of the upper and lower chain conveyors 200 and 100 and thussuccessively pass via the grinding units 300, whereby the seat surfacesformed on the opposite ends of the compression line springs are ground.

Before operation S120 is conducted, the operator rotates the third screwshaft 350 or the fourth screw shaft 380 and thus adjusts the position ofthe grinding unit 300, thereby adjusting the depth of cut.

As described above, in the apparatus and method for grinding compressionline springs according to the present invention, when it is required ina separate operation to grind compression line springs having adifferent dimension, appropriate conditions for grinding the compressionline springs can be easily embodied by simple setting manipulationwithout need for the conventional complex operation of replacing aturntable with another one. Therefore, the efficiency of the operationof grinding compression line springs can be enhanced. Moreover, becausethere is no need for preparing different kinds of turntables, relatedcosts can be reduced.

Although the embodiment of the present invention has been disclosed forillustrative purposes, it will be appreciated that the present inventionis not limited thereto, and those skilled in the art will appreciatethat various modifications, additions and substitutions are possible,without departing from the scope and spirit of the invention.

What is claimed is:
 1. An apparatus for grinding a compression linespring, comprising: a lower chain conveyor (100) including a pair ofchain units (110) and (110′) provided facing each other at positionsspaced apart from each other, each of the chain units (110) and (110′)comprising a plurality of first V-shaped blocks (115) for supportingcompression line springs; an upper chain conveyor (200) including a pairof chain units (210) and (210′) provided facing each other at positionsspaced apart from each other, each of the chain units (210) and (210′)comprising a plurality of second V-shaped blocks (215) for compressingdownward upper portions of the compression line springs seated on thefirst V-shaped blocks (115) and thus supporting the compression linesprings; and a plurality of grinding units (300) for grinding seatsurfaces formed on opposite ends of the compression line springs thatare moved by the lower chain conveyor (100) and the upper chain conveyor(200).
 2. The apparatus of claim 1, wherein, of the chain units (110)and (110′) of the lower chain conveyor (100), the front chain unit (110)is configured so as to be movable toward or away from the rear chainunit (110′) depending on a length of the compression line springs, andof the chain units (210) and (210′) of the upper chain conveyor (200),the front chain unit (210) is configured so as to be movable toward oraway from the rear chain unit (110′) depending on the length of thecompression line springs.
 3. The apparatus of claim 2, wherein the frontchain unit (110) of the lower chain conveyor (100) is coupled to one ormore first screw shafts (130) and (130′) by a transfer nut (140), thefirst screw shafts (130) and (130′) horizontally extending through thechain unit (110′), the front chain unit (210) of the upper chainconveyor (200) is coupled to a second screw shaft (230) by a transfernut (240), the second screw shaft (230) horizontally extending throughthe rear chain unit (210′), and the first screw shafts (130) and (130′)and a second screw shaft (230) are connected to each other by a belt(150) and thus interlocked with each other.
 4. The apparatus of claim 3,wherein the second screw shaft (230) is connected to a motor (250) androtated by operation of the motor (250).
 5. The apparatus of claim 1,further comprising: a plurality of compression blocks (260) provided inthe upper chain conveyor (200) and pressing a chain (214) downward sothat the second V-shaped blocks (215) are brought into close contactwith the compression line springs; and a plurality of springs (270)installed in the upper chain conveyor (200) and elastically supportingthe compression blocks (260).
 6. The apparatus of claim 5, wherein theplurality of compression blocks (260) are coupled to each other by a pin(261).
 7. The apparatus of claim 1, further comprising: a distanceadjustment means (500) for moving the upper chain conveyor (200) upwardor downward and adjusting a distance between the first V-shaped blocks(115) and the second V-shaped blocks (215).
 8. The apparatus of claim 7,wherein the distance adjustment means (500) comprises: a lift frame(510) coupled to the upper chain conveyor (200); a pair of rails (520)installed on an upper end of the lift frame (510) and extending in aleft-right direction; a pair of inclined blocks (531) and (532) providedso as to be movable along the rails (520), with inclined rails (531′)and (532′) installed on upper ends of the respective inclined blocks(531) and (532); a fifth screw shaft (540) configured to pass throughthe two inclined blocks (531) and (532), the fifth screw shaft (540)rotating when an operator manipulates a handle (543) and thus moving theinclined blocks (531) and (532) such that the inclined blocks (531) and(532) move toward or away from each other; and a pair of fixed blocks(551) and (552) installed on a fixed frame (560) above the respectivetwo inclined blocks (531) and (532), the fixed blocks (551) and (552)being respectively coupled to the inclined rails (531′) and (532′) sothat when the inclined blocks (531) and (532) are moved, the fixedblocks (551) and (552) guide the inclined blocks (531) and (532) suchthat the inclined blocks (531) and (532) are moved upward or downward byan inclination angle (⊖) of the inclined rails (531′) and (532′).
 9. Theapparatus of claim 1, further comprising: a motor (400) providing powerfor driving the lower chain conveyor (100) and the upper chain conveyor(200); a reducer (410) connected to the motor (400) and including twooutput shafts (411) and (412); a first universal joint (420) connectingthe output shaft (411) of the reducer (410) to a spline shaft (118)extending from the lower chain conveyor (100); and a second universaljoint (430) connecting the output shaft (412) of the reducer (410) to aspline shaft (218) extending from the upper chain conveyor (200). 10.The apparatus of claim 1, further comprising: a transfer table (330)having an upper surface on which the plurality of grinding units (300)is installed; a transfer nut (340) fastened to a lower surface of thetransfer table (330); and a third screw shaft (350) coupled to thetransfer nut (340), the third screw shaft (350) rotating by manipulationof the operator and thus moving the transfer nut (340) and the transfertable (330) toward or away from the compression line springs.
 11. Theapparatus of claim 10, further comprising: a fastening plate (360)installed on a lower end of each of the grinding units (300); a transfernut (370) installed under a lower surface of the fastening plate (360);and a fourth screw shaft (380) installed on the transfer table (330) andcoupled to the transfer nut (370), the fourth screw shaft (380) rotatingby manipulation of the operator and thus transferring the transfer nut(370).
 12. A method for grinding a compression line spring, comprising:an operation (S110) of fixing compression line springs in place usingfirst V-shaped blocks (115) and second V-shaped blocks (215)respectively provided in a lower chain conveyor (100) and an upper chainconveyor (200) and transferring the compression line springs in ahorizontal direction using the lower chain conveyor (100) and the upperchain conveyor (200); and an operation (S120) of grinding, usinggrinding units (300), seat surfaces formed on opposite ends of thecompression line springs that are transferred in the operation (S110).13. The method of claim 12, further comprising, an operation (S101) ofadjusting both a distance between a front chain unit (110) and a rearchain unit (110′) of the lower chain conveyor (100) and a distancebetween a front chain unit (210) and a rear chain unit (210′) of theupper chain conveyor (200) before the operation (S110) is conducted. 14.The method of claim 12, further comprising: an operation (S102) ofadjusting a height of the upper chain conveyor (200) depending on anouter diameter of the compression line springs before the operation(S110) is conducted.